Centrifugal concentrator



Dec. 24, 1968 o. M. ARNOLD CENTRIFUGAL CONCENTRATOR 2 Sheets-Sheet 1 Filed Oct. 10, 1967 IINVENTOR. OrZan M flrnolci AZLMMJ Dec. 24, 1968 o. M. ARNOLD CENTRIFUGAL CONCENTRATOR 2 Sheets-Sheet 2 Filed Oct. 10, 1967 United States Patent 3,417,871 CENTRIFUGAL CONCENTRATOR Orlan M. Arnold, Grosse Pointe Park, Mich., assignor to Ajem Laboratories, Inc., Livonia, Mich. Filed Oct. 10, 1967, Ser. No. 674,328 7 Claims. (Cl. 210--512) ABSTRACT OF THE DISCLOSURE A centrifugal concentrator for clarifying liquids wherein the centrifugal concentrator utilizes a high pressure tangential inlet flow of liquid containing solid suspensions to create a vortexing action within a conically shaped separating chamber. The solid particles suspended in the li uid, due to centrifugal force, migrate outward toward the confining wall of the separating chamber and then settle along the inwardly slopng wall of a lower part of the chamber, where they are removed through an exit port. Provision is made to agitate the concentrated slurry within the exit port to prevent clogging and coalesence of the solid particles, thereby to eliminate constriction of the outlet flow and prevent liquid build up within the separating chamber which would adversely affect the clarity of the clear liquid being removed.

This invention relates to centrifugal concentrators and more particularly to centrifugal concentrators relying on high pressure tangential inlet flow to create a vortexing action within the separation chamber to separate suspended solid particles from the carrying liquid.

Centrifugal separators or concentrators utilizing high inlet pressures to create a vortexing action within the separation chamber are in general and large scale use today. Concentrators of this type are generally effective in removing solid contaminants from the carrying liquid if the solids are of fairly uniform and relatively small size. However, in applications where solid particles having irregular shapes, or where other unexpected solid materials are in the liquid to be clarified, or can be deposited in the liquid before it enters the concentrator, then, there may be a tendency to clog and back up. Further, where solid particles to be removed are organic compositions, there may be a tendency for these solids to coalesce and conglomerate so as to stop up the exit outlet. This problem of a constricted flow in the outlet causes a build up of liquid within the separation chamber that affects the clarity of the liquid being removed from the upper portion of the separation chamber. As this reduces the efliciency of the centrifugal concentrator, it may be necessary to discontinue operation of the concentrator, dismantel it and remove the blockage.

It is therefore an object of the present invention to provide a centrifugal concentrator wherein provision is made to eliminate clogging of the solid particles at the concentrated slurry exit.

It is a further object of the present invention to provide a centrifugal concentrator wherein the efliciency of the unit in removing solid particles is maintained by eliminating the tendency of the concentrated liquid to back up within the separation chamber.

A still further object of the present invention is to provide a centrifugal concentrator having none of the abovedescribed disadvantages of the prior art.

In accordance with one embodiment of the present invention, a centrifugal concentrator is provided having a generally cylindrical inlet scroll with a tangenial liquid inlet and a lower, generally conically shaped separation chamber. Liquid containing suspended solid particles, which enters under high pressure through the tangential inlet, causes the body of liquid in the chamber to vortex.

The solid particles migrate radially outward, due to centrifugal chamber force, toward the confining wall of the separation chamber and settle toward the lower end of the chamber adjacent to the outlet exit. The exit port is provided with a vertically movable plunger to agitate and break up any conglomeration of the solid particles to keep the exit port free and maintain a continuous removal of the concentrated slurry.

In the specification and in the accompanying drawings, there is described and shown an illustrative embodiment of the invention and various modifications thereof are suggested, but it is to be understood that these are not intended to be exhaustive, but on the contrary are given for purposes of illustration in order that others skilled in the art may fully understand the invention so that they may modify and adapt it in various forms, each as may be best suited to the conditions of a particular use.

The various objects, aspects and advantages of the present invention will be more fully understood from a consideration of the following specification in conjunction with the accompanying drawings in which:

FIGURE 1 is a perspective view showing a centrifugal concentrator embodying the present invention;

FIGURE 2 is a view, partly in section, taken on line 2-2 of FIGURE 1 showing the slurry outlet area of the centrifugal concentrator;

FIGURE 3 is a view similar to FIGURE J2 showing an alternate embodiment of the lower outlet area;

FIGURE 4 is a view similar to FIGURE 2 showing still another embodiment of the lower outlet area;

FIGURE 5 is a view similar to FIGURE 2 showing still another embodiment of the outlet area;

FIGURE 6 is an elevational view, partly in section, of the lower portion of a centrifugal concentrator showing another embodiment of the slurry outlet area; and

FIGURE 7 is a sectional view taken on line 77 of FIGURE 6.

Referring now to the drawing and more particularly to FIGURE 1, there is shown a centrifugal concentrator 10 having a generally cylindrical inlet scroll 12, a cylindrical separating chamber 14 and a conically shaped separating chamber 16. A lower conically shaped extension 18 is also provided, which communicates with the concentrated slurry outlet 20, where the solid particles, that have been concentrated are removed. The inlet scroll 12 has a flange 22 on its lower portion that mates with flange 24 on the upper portion of the cylindrical chamber 14. These are clamped together, e.g., by attaching bolts (not shown).

The flanges 26 and 28 on the lower portion of the cylindrical chamber 14 and the upper portion of conical chamber 16 and the flanges 30, 32, 34 and 36 are similarly provided for connection between the conically shaped separating chamber 16, lower extension chamber 18 and slurry outlet 20, respectively. The centrifugal separator can thus be disassembled easily for maintenance and/ or selective replacement of the various sections.

The inlet scroll 12 is provided with a tangential fluid inlet 38 through which the solids-containing liquid is admitted, advantageously under pressure, from a suitable pump (not shown). Due to its high pressure and tangential introduction into the inlet scroll 12, the liquid begins to form a vortex within the concentrator. Solid particles carried by the liquid are thus subjected to a centrifugal force, which causes them to migrate outward toward the wall of the concentrator. The solid particles then settle along the inwardly sloping walls of the conical sections 16 and 18 and are removed through slurry exit 20'. The liquid toward the center of the concentrator is relatively clear and is withdrawn through clarified liquid exit tube 40 and piped away or collected in a suitable vessel (not shown).

It is important to avoid constriction in slurry outlet 20, even for a short time, as any liquid buildup in the separator due to a constricted flow at the outlet will effect the clarity of the liquid drawn off through the clarified liquid exit tube 40. Thus, in order to maintain the efliciency of the unit the ratio of solids-containing liquid entering through inlet 38, to the clarified liquid exiting from tube and the concentrated slurry exiting from outlet 20 must be maintained. When, due to the nature of the solids being removed or to unexpected solids in the liquid, a concentration or coalescence of solids occurs in the slurry outlet, it may be necessary to break up such congestion to maintain a constant flow at the slurry outlet 20.

Referring now to FIGURE 2, a plunger rod 42, is disposed along the central axis of outlet 20 and is adapted to be reciprocated vertically when one needs to break up solids that are collecting and wedging into the bottom exit throat of the slurry outlet. Rod 42 has its lower end 44 slidably received within support bushing 46 which is mounted by spider 48 within slurry outlet extension tube 50. The rod 42 includes, along its midportion, a ferromagnetic armature or slug 52. Magnetic coil 54, mounted in an annular housing and energized by a suitable electric power source (not shown), surrounds the lower extension tube 50 and the ferro-magnetic slug 52. A power source is intermittently connected to coil 54 to activate it intermittently, expanding and collapsing a magnetic field that acts on the slug 52 to cause it to act as a solenoid motor, i.e., to rise and fall as the field intensifies and relaxes.

Plunger rod 42 in this embodiment is rigidly secured to the slug so that it reciprocates up and down with slug 52 and upper end 56 of the rod then acts as a ram to break up any accumulations or conglomerated solids that may be clogging outlet 20. Since the rod 42 is held upright by bushing 46 and the bushing is located near the lower end of rod 42, the vertical reciprocation of the rod and slug produce a limited gyrating movement, which enhances'the ability of the rod to break up solids and clear outlet 20.

In an alternate embodiment shown in FIGURE 3, plunger rod 42a, slidably received within bushing 46a, as in the embodiment of FIGURE 2, receives its vertical reciprocating motion through linkage 58 and motor 60. Linkage 58 includes lever 62 pivotally mounted as at 64 to the extension 50a. One end of lever 62 pivotally engages, as at 70, plunger 42a, while wheel 72 rotatably mounted on the other end, bears on the eccentric 74. Motor has an eccentric wheel 74 on output shaft 76 that engages the bearing wheel 72. Thus, as the eccentric 74 rotates, bearing wheel 72, and its lever 62, reciprocate up and down about pivot axis 64. This reciprocating movement is transferred by lever 62 to plunger rod 42a which, like the plunger in the embodiment of FIG- URE 2, breaks up any accumulation or conglomeration of solids at the exit port 20a.

A flexible sleeve 78 surrounds the exterior portion of the lever 62 to prevent leakage of liquid from outlet 20a while permitting lever 62 to pivot freely about pivot 64.

Referring now to FIGURE 4, there is shown another alternate embodiment wherein lower outlet portion 20b has positioned therein a plurality of rotating impellers 80 pitched so as to impel liquid downward. This figure also illustrates another optional feature in that the outlet extension 5012 includes elbow connection 84 and lateral exit tube 86. Impellers 80 are mounted on drive shaft 88 extending through and rotatably mounted in elbow connection 84. Motor 90 connected to shaft 88 in any suitable manner, e.g., a belt drive, rotates shaft 88 and impellers 80. A seal 92, where shaft 88 enters the elbow 84 prevents leakage. Thus, as the impeller blades are rotated within slurry outlet 2%, the blades cut through conglomerated solids and also, advantageously due to their pitch, impel the concentrated slurry downward so that it may exit more rapidly and continuously through lateral exit tube 86.

Referring now to FIGURE 5, there is shown another embodiment wherein a high energy liquid spray is used to break up conglomeration of solids. Tube 94 which supplies a liquid under pressure extends through elbow 840 in lower outlet extension 500. Spray head 102 seals the upper end of tube 94, but liquid outlet ports are arranged around the circumference at the upper end of tube 94, thus directing the liquid from outlet ports 100 to circumferentially arranged spray ports 104 and downward into the slurry outlet 20c. The resulting spray is under sufiiciently high pressure to break up conglomerated solids and also drives them downward through the outlet extension 500, into lateral exit tube 106.

It is to be understood that while a single spray head has been shown for convenience, a plurality of spray heads arranged along the tube 94 may be employed. It is to be further understood that with each of the embodiments described thus far, the liquid slurry exits through an annular space surrounding the shaft extending into the slurry outlet. The dimension of this annular space should be large enough to maintain a ratio of slurry outlet to the liquid coming into the centrifugal separator through inlet 38.

Since the liquid slurry exiting from the outlet tube is swirling rapidly as a result of the action in the centrifugal concentrator, oftentimes, depending upon the type of solids being removed it has enough inherent energy to break up any conglomerated solids that may accumulate in the slurry outlet. However, any constriction in the flow in this area as noted above, may effect clarity of the liquid being removed.

Therefore, in another embodiment shown in FIGURES 6 and 7, and apparatus is shown that utilizes the inherent energy of the swirling liquid to prevent clogging. An outlet accumulation sleeve having an internal diameter considerably larger than the outlet tube diameter is positioned so that it surrounds the lower conically shaped slurry outlet 20d. Accumulation sleeve 110 is attached to the lower portion of the concentrator by spider 112 and allows the concentrated slurry, to exit freely from the outlet portion 20d. The concentrated slurry, since it is swirling rapidly, leaves the area 20d in a conical spray that becomes wider than the mouth of the outlet portion of slurry outlet 20d. Thus the greater collection volume available within accumulation sleeve 110 relieves the constriction usually associated with a tubular extension of the same diameter as the outlet that is normally used to remove the slurry fro-m the centrifugal concentrator. In this manner, as the flow is unconstricted, the swirling liquid within the concentrator itself prevents clogging and thus eliminates the build-up within the concentrator that effects the clarity of the liquid being removed. Thus, as the slurry accumulates within the sleeve 110 it is drawn off through lower outlet 114 to a suitable collecting vessel (not shown).

It is thus seen that a centrifugal concentrator is probided with means near the concentrated slurry outlet to eliminate any unwanted clogging or conglomeration of the solid particles being removed. Thus, the ratio of solids-containing liquid entering the inlet to the clarified liquid drawn off and to the concentrated slurry withdrawn from the bottom is maintained constant. When this ratio is kept constant, the efficiency of the concentrator in removing solid particles from the carrying liquid may be maintained and the clarity of the liquid drawn off through the clarified liquid exit tube can be maintained.

While there have been described what are at present considered to be the preferred embodiments of this invention, it wil be obvious to those skilled in the art that various changes and modifications may be made therein What is claimed is:

1. A centrifugal concentrator for separating solid particles from a liquid comprising an inlet chamber including means for tangentially introducing a stream of solids-containing liquid under pressure to the upper portion of said inlet chamber, a generally frusto-conical separation chamber having its larger end in fluid communication with the lower portion of said inlet chamber, a clarified liquid exit conduit extending through said inlet chamber and into said separation chamber axially thereof for removing clarified liquid, an outlet conduit near the smaller end of said separation chamber for removing concentrated solid particles and wherein concentration of the solid particles in the liquid is effected by vortexing of solidscontaiuing liquid in the inlet chamber and in said frustoconical chamber whereby to cause said solid particles to migrate by centrifugal force outward toward the confining wall of said chamber there to settle downward along its sloping wall and collect near the outlet, thereby leaving relatively clarified liquid in the vicinity of the exit conduit near the central axis of said chamber which is characterized by the combination therewith of:

means near said outlet and spaced from the wall of said outlet conduit to agitate the concentrated liquid-solid mixture in passing to the exit to prevent clogging of said outlet and to maintain greater uniformity in the liquid drawn off through said clarified liquid exit conduit.

2. The centrifugal concentrator of claim 1 wherein said means to agitate said liquid-solid mixture includes a plunger rod within said outlet adapted to reciprocate vertically, thereby to break up any concentrations of solid particles in said outlet.

3. The centrifugal concentrator of claim 2 wherein said plunger rod is slidably disposed within said outlet and includes at least a portion having induced magnetic properties, magnetic field energizing means surrounding said plunger rod and near said magnetic portion, whereby when said magnetic field energizing means is intermittently energized, said plunger rod reciprocates to break up concentrations of solid particles.

4. The centrifugal concentrator of claim 2 wherein said plunger rod is slidably disposed within said outlet, a lever having one end pivotally connected to said plunger rod, said lever being pivotally mounted adjacent said outlet, means operably engaging said lever to cause said lever to pivot reciprocably about its pivot, whereby said plunger rod reciprocates to break up concentrations of solid particles.

5. The centrifugal concentrator of claim 4 wherein said means operably engaging said lever includes an eccentric mounted on the output shaft of a motor and adapted to rotate, said eccentric being in contact with a bearing wheel rotatably mounted on the other end of said lever, whereby rotation of said eccentric causes said other end of said lever to rise and fall as the eccentric rotates thereby imparting a reciprocating pivoting motion to said lever.

6. The centrifugal concentrator of claim 1 wherein said means to agitate said liquid-solid mixture includes a hollow liquid supply shaft extending into said outlet, a spray head on said shaft in communication with the hollow interior of said shaft and adapted to direct liquid under pressure downward into said outlet, thereby to break up concentrations of solid particles and assist in flushing away said solid particles.

7. The centrifugal concentrator of claim 1 wherein said means to agitate said liquid-solid mixture includes a shaft rotatably mounted within said outlet, a plurality of impeller blades extending from said shaft, said impeller blades being so pitched as to impel fluid toward said outlet, means to impart rotation to said shaft, whereby when said shaft and impeller blades rotate said blades cut through concentrations of solid particles to break them up and impel said solid particles out said slurry outlet.

References Cited UNITED STATES PATENTS 2,709,397 5/1955 Banning 2105l2 X 2,781,910 2/1957 Fontein 210512 X 2,848,066 8/1958 Allander et al. 296 2,953,248 9/1960 Troland 210-512 X 3,000,036 9/ 1961 De Benedetti 55295 X 3,016,962 1/1962 Lummus et al. 210512 X 3,243,043 3/1966 Thompson et al. 2105 12 X 3,276,592 10/1966 Neuman 210512 X FOREIGN PATENTS 1,299,115 6/1962 France.

REUBEN FRIEDMAN, Primary Examiner.

J. DE CESARE, Assistant Examiner.

US. Cl. X.R. 

